Final answer:
The acceleration of a car that goes from rest to 20 m/s in 8 seconds is 2.5 m/s².
Step-by-step explanation:
The acceleration of a car can be calculated using the formula a = (v - u) / t, where v is the final velocity, u is the initial velocity, and t is the time taken to change the velocity from u to v.
In the given problem, the car accelerates from rest (initial velocity u = 0 m/s) to a final velocity of v = 20 m/s in a time of t = 8.0 seconds. We substitute these values into the acceleration formula: a = (20 m/s - 0 m/s) / 8.0 s = 20 m/s / 8.0 s.
Therefore, the acceleration of the car is 2.5 m/s².